The importance of dung beetles and arthropod communities on degradation of cattle dung pats in eastern South Dakota

Abstract

Background. Dung accumulation in rangelands can suppress plant growth, foul pastures, and increase pest pressure. Here, we describe the arthropod community of dung in eastern South Dakota, and quantify their contributions to dung degradation using an exclusion cage design. Methods. Various arthropod community and degradation characteristics were mea- sured in caged and uncaged dung pats over time in early and late summer. Results. A total of 86,969 specimens were collected across 109 morphospecies (13 orders) of arthropods, and cages effectively reduced arthropod abundance, species richness, and diversity. Uncaged dung pats degraded significantly faster than the caged pats, with the largest difference occurring within 2 d of pat deposition. Dung organic matter was degraded more slowly (by 33-38 d) in the caged pats than where insects had free access to the pats. Although dung beetles only represented 1.5-3% of total arthropod abundance, they were significantly correlated to more abundant and complex total arthropod communities. Discussion. A diverse community contributes to dung degradation in rangelands, and their early colonization is key to maximizing this ecosystem service.